BMP

From Just Solve the File Format Problem
(Difference between revisions)
Jump to: navigation, search
m
Line 5: Line 5:
 
|pronom={{PRONOM|fmt/116}}, others
 
|pronom={{PRONOM|fmt/116}}, others
 
}}
 
}}
 +
== Overview ==
 
'''BMP''' is a family of simple raster graphics image file formats designed to store bitmap digital images independently of a display device.  BMP was originally and is primarily used on Microsoft Windows and OS/2 operating systems. The format is sometimes known as Device-Independent Bitmap (DIB), since, when loaded into memory using Windows software, the image is held as a DIB structure.
 
'''BMP''' is a family of simple raster graphics image file formats designed to store bitmap digital images independently of a display device.  BMP was originally and is primarily used on Microsoft Windows and OS/2 operating systems. The format is sometimes known as Device-Independent Bitmap (DIB), since, when loaded into memory using Windows software, the image is held as a DIB structure.
  
Line 28: Line 29:
 
* Info header size: 40
 
* Info header size: 40
 
* Info header name: BITMAPINFOHEADER
 
* Info header name: BITMAPINFOHEADER
* PRONOM: {{PRONOM|fmt/116}} (1, 4, 8, 24 bits/pixel), {{PRONOM|fmt/117}} (16, 32 bits/pixel)
+
* PRONOM: {{PRONOM|fmt/116}}, {{PRONOM|fmt/117}}
  
This is by far the most widely used version of BMP.
+
This is by far the most widely used version of BMP. It was introduced with Windows 3.x. Windows NT extended it to support 16 and 32 bits/pixel.
  
When 16 or 32 bits/pixel is supported, the format may be known as "BMP 3.0 NT".
+
Windows CE also extended it, for example to allow 2 bits/pixel, but its extensions were not migrated to the BMP v4 and v5 formats.
  
Note: It's possible that some OS/2 BMP 2.0 files also have a header size of 40.
+
If the compression type is 3 and the bit depth is 1, or the compression type is 4 and the bit depth is 24, then the file should be processed as an OS/2 2.0 BMP.
  
 
=== Windows BMP v4 ===
 
=== Windows BMP v4 ===
Line 51: Line 52:
 
* PRONOM: {{PRONOM|fmt/114}}
 
* PRONOM: {{PRONOM|fmt/114}}
  
Based on limited information, this format does not use the usual 14-byte header. The file extension may be '''.bmp''' or '''.ddb'''.
+
This is the bitmap file format used by Windows 1.0. It's not really a BMP format. It has a 10-byte file header, and is also called "DDB" (Device-Dependent Bitmap).
  
 
=== OS/2 BMP 2.0 ===
 
=== OS/2 BMP 2.0 ===
* Info header size: 16, 40, 48, or 64 (?)
+
* Info header size: 16–64 (16, 40, 48, and 64 may be most common)
 
* Info header name: BITMAPCOREHEADER2 or OS22XBITMAPHEADER
 
* Info header name: BITMAPCOREHEADER2 or OS22XBITMAPHEADER
 
* PRONOM: {{PRONOM|x-fmt/270}}
 
* PRONOM: {{PRONOM|x-fmt/270}}
Line 76: Line 77:
 
* [http://msdn.microsoft.com/en-us/library/dd183372%28v=vs.85%29.aspx BITMAPCOREHEADER]
 
* [http://msdn.microsoft.com/en-us/library/dd183372%28v=vs.85%29.aspx BITMAPCOREHEADER]
 
* [http://msdn.microsoft.com/en-us/library/dd183376%28v=vs.85%29.aspx BITMAPINFOHEADER]
 
* [http://msdn.microsoft.com/en-us/library/dd183376%28v=vs.85%29.aspx BITMAPINFOHEADER]
 +
* [http://msdn.microsoft.com/en-us/library/aa452885.aspx BITMAPINFOHEADER (Windows CE 5.0)]
 
* [http://msdn.microsoft.com/en-us/library/dd183380%28v=vs.85%29.aspx BITMAPV4HEADER]
 
* [http://msdn.microsoft.com/en-us/library/dd183380%28v=vs.85%29.aspx BITMAPV4HEADER]
 
* [http://msdn.microsoft.com/en-us/library/dd183381%28v=vs.85%29.aspx BITMAPV5HEADER]
 
* [http://msdn.microsoft.com/en-us/library/dd183381%28v=vs.85%29.aspx BITMAPV5HEADER]

Revision as of 04:41, 7 March 2013

File Format
Name BMP
Ontology
Extension(s) .bmp
.dib
.rle
PRONOM fmt/116, others

Contents

Overview

BMP is a family of simple raster graphics image file formats designed to store bitmap digital images independently of a display device. BMP was originally and is primarily used on Microsoft Windows and OS/2 operating systems. The format is sometimes known as Device-Independent Bitmap (DIB), since, when loaded into memory using Windows software, the image is held as a DIB structure.

Identification

No MIME type has been officially registered. Strings found in practice are: image/bmp; image/x-bmp; image/x-ms-bmp

The standard file extension is .bmp. Reportedly, .dib and .rle have occasionally been used.

BMP files start with bytes 'B' 'M' ?? ?? 00 00 00 00.

Well-known versions

Unless otherwise indicated, BMP files all use a common 14-byte file header, named BITMAPFILEHEADER. Following that is the "Info header", which begins with a 4-byte integer indicating its size. The Info header size (mostly) reveals the version of BMP that the file uses.

Windows BMP v2

  • Info header size: 12
  • Info header name: BITMAPCOREHEADER or OS21XBITMAPHEADER
  • PRONOM: fmt/115

Also known as OS/2 BMP 1.0.

Windows BMP v3

  • Info header size: 40
  • Info header name: BITMAPINFOHEADER
  • PRONOM: fmt/116, fmt/117

This is by far the most widely used version of BMP. It was introduced with Windows 3.x. Windows NT extended it to support 16 and 32 bits/pixel.

Windows CE also extended it, for example to allow 2 bits/pixel, but its extensions were not migrated to the BMP v4 and v5 formats.

If the compression type is 3 and the bit depth is 1, or the compression type is 4 and the bit depth is 24, then the file should be processed as an OS/2 2.0 BMP.

Windows BMP v4

  • Info header size: 108
  • Info header name: BITMAPV4HEADER
  • PRONOM: fmt/118

Windows BMP v5

  • Info header size: 124
  • Info header name: BITMAPV5HEADER
  • PRONOM: fmt/119

Other versions

Windows BMP v1

This is the bitmap file format used by Windows 1.0. It's not really a BMP format. It has a 10-byte file header, and is also called "DDB" (Device-Dependent Bitmap).

OS/2 BMP 2.0

  • Info header size: 16–64 (16, 40, 48, and 64 may be most common)
  • Info header name: BITMAPCOREHEADER2 or OS22XBITMAPHEADER
  • PRONOM: x-fmt/270

See OS/2 BMP.

BITMAPV2INFOHEADER

  • Info header size: 52
  • Info header name: BITMAPV2INFOHEADER

No details known.

BITMAPV3INFOHEADER

  • Info header size: 56
  • Info header name: BITMAPV3INFOHEADER

No details known.

Specifications

Sample images

References

Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox